Chucking device for crank shafts



Aug. 6, 1929. w. F. GROENE CHUCKING DEVICE FOR CRANK SHAFTS Filed June 6, 1927 I5 Sheets-Sheet 1 INVENTOR. 7M

' ATTORNEY.

6, w. F. GROENE CHUCKING DEVICE FOR CRANK SHAFT Filed June 6, 25 Sheets-Sheet 2 Patented Aug. 6, 1929.-

UNITED STATES PATENT OFFICE.

WILLIAM F. GROENE, OF CINCINNATI, OHIO, ASSIGNOR TOTHE R. K. LE BLOND KA- CHDTE TOOL COMPANY, OF CINCINNATI, OHIO, A CORPORATION OF DELAWARE.

CHUC'KING DEVICE FOR CRANK SHAI'TS.

Application filed June 6, 1927. Serial No. 196,806.

My invention relates to chucking devices for crank shaft lathes in which it is desired a true center, and a so to grip with'an equal izing action a check of the shaft'andhold it so that one of the off set crank ins is on the true center of rotation of the c uck.

It is my object to operate my chuck by suitable-power means, such as compressed air, and additionally to apply the compressed air selectively to the crank pin gripping member and the cheek gripping and centering elements. Thus, in the illustrated adaptation of my invention, I- provide two air cylinders and pistons with the piston shaft of one operating .through'the piston' shaft of the other.

It is my object, as stated, to apply pressure from a power source, such as compressed air, through an equalizer or pivotally actuated cross head, so that inequalities in the face of the crank shaftcheek will be compensated for by applying equal pressure against the. edges of the cheek, even if one edge is slightly difierent from the other. It is also my object to apply the force to the gripping dogs in such a way, that with in the fact that an equalizer bar or pivotally operated cross head, used to ap ly gripping pressure to a plurality of mem rs, will, it no means is employed to prevent it, give way and rock on its pivot, so as to equalize an unbalanced strain laced on the gripped element, thus destroying the centering thereof.

An object of my invention is to provide.

a simple structure which will be very positive in its chucking, and yet simple to release.

I accomplish my objects by that certain construction and arrangement of parts to be hereinafter more specifically pointed out and claimed In the drawings Figure 1 is a plan view of the chucking device.

Figure 2 is a Figure 1..

Figure 3 is an endiielevation operating end ofthe device. I

I have iHustrated'a'pair' of air cylinders 1 and 2, and the power means for operating taken at the my device. The piston "shaft or ro e ofsection on the line 2 2 of the cylinder 1 passes through the center of I the piston 4, in the cylinder 2, andthe piston' rod of the piston- 4 is asleeve '5' through wl ili plh-the'rod 3 asses.

e chuck bo y omittin the air-c lin ders, may be divided into m5 parts, the body port on 6, and the body portion 7 same body portions being connected together by webs 8 and 9, which webs may be as long as de sired to accommodate the projection of the chucked member.

Mounted on a pin 10, within the body portion 6, at the air cylinderend, is a' lever 11,

which has its central portion formed into a yoke. The sleeve rod 5 is cut' down at its;

ends as at 12, forming a shoulder which will engage the side walls of the yoke, with the en 12 passing through the yoke. nut 13 on the inner end of the sleeve portion 12,

engages the yoke on the opposite side to the shoulder.

As so constructed, the sleeve, when pushed The lower end of the lever is connected to an operating rod 14, which passes throu h a bushing 15 in the web 9 of the chuck bo y,

and into the chuck body portion 7.

The chuck bod portion 7 is formed with clearance, in w ich swings a plate '16 mounted on a pivot stud 17. The plate is fitted on its central under portion with a half bushing piece 18, which will be of an internal circumference, suitable for the pin of the crank shaft to be chucked.

Connected to the end of the late 16 is a link 19 which depends within t e clearance space in the chuck body portion 7, 'to a position where a hole 20 in the link is engaged by the outer end of the operating rod 14.

The inner end of the bushin 15 may be squared to prevent the rod 14 rom revolving, and the inner end 'of the rod 14 may be squared,as indicated at 21.

.The tipof the rod 14, as noted at 14- is cut to form a wedge, which, when the tip of the rod is forced through the hole in the link 19, will force the link downwardly.

Thus, the rocking of the lever 11 will I push upon the rod 14, which will pull down on the plate 16.

The chuck body portion 7 is provided with a portion just behind its front face, which is curved out as indicated at 7*, and this curved out portion is fitted with a half bushing 18, which is alike to the half bushing 18, is arranged to fit the crank pin to be chucked.

When an operator has set the end bearing, szfy of a crank shaft, into the socket formed by the bushing piece 18*, and then applies the air to the near air cylinder, the result will be to clamp the crank bearing in place. During this operation the shaft may be moved to a position with the cheek 22 thereo't' across the center of the chuck body so that the pin 23, which is located ofl -center of the chucked pin or hearing, will be at the exact center of rotation of the chuck body.

It remains then to apply an equalized pressure to the opposite faces of the cheek, to hold the shaft in position to be worked upon by a tool applied with relation to the center of the chuck body.

This gripping action 1s applied by means of two dogs 24, 24, which are pivoted at 25, 25, and have faces 26, which will engage both edges of the shaft check.

The dogs are engaged by wedge like ends 27, upon two rods 28, which, as will be described, are 0 erated from the far air cylinder. In or er to keep the dogs against the Wedge ends, thus causing them to open, when the wedges are removed, I provide an abutment late 29 in the lower face of the interior 0 the chuck body portion 7, and form spring sockets 30 in the lower ends of the dogs. Thimbles 31, 31, with ,spiral springs 32 therein, are set into the sockets, so t at the thimbles press against the plate29. The result of this .structure is to tend to swing the upper ends of the dogs outwardl To operate the rods 28, whose Wedge ends protrude from the chuck body portion 7, so as to engage the dogs, I provide an equalizer bar or pivotally actuated cross head, in the form of a member having two forked ends 32,32, connected by a body portion 33, which is formed with a central yoke portion 34. Across this yoke portion extends a pivot pin 35.

The piston rod 3 is secured in a socket in i a short bar 36,.which bar extends into the yoke space in the equalizer bar or cross head,-and is also pivoted on the pin 35.

The forked outer ends of the equalizer bar engages in socket elements 28 secured .over a reduced section 28, of the two rods 28. The fork tines are curved, and so are the socket elements, so that the tines canwhich will cause the rod 3 to push on the center of the cross head, thus causing the forked ends of the cross head to push the two rods 28 outwardly, with the final re sult of wedging the dogs into engagement with-the cheek.

If one of the dogs comes into engagement with the cheek before the other, it will cease to travel, and the cross head will rock to bring up the other dog to engagement, and in this way the two dogs will be caused to press against'the edges of the crank shaft check with equal force, irrespective of slight inequalities in the edges of the cheeks, and furthermore, that this action will not dislodgethe shaft check from its centered position. V

The employment of wedges at the end of the equalizer rods results in the application of force in such a way that strains imparted to the chucked shaft cannot swing the equalizer cross head to a position to permit the shaft to swing off of the desired center, because the force applied to the dogs will never be suflicient to back out the wedges. The rotation of the chuck body is accomplished in the usual manner, andthe air applied by means of slip rin s or otherwise, in a manner well known in the art. y

3 Having thus described my invention what I claim as new and desire to secure by Letters Patent is d 1. In a crank shaft lathe, the combination with the chuck body, of pivoted means thereon to clamp about a pin or bearing portion thereof, and additional means to grip in se quence with the other means the adjacent cheek portion thereof on both sides with equal pressure, and ower means applied axially of the body Ior operating both of said means. i

2. In a crank shaft lathe, the combination with the chuck body, of pivoted means thereon to clamp about a pin or hearing portion thereof, and additional means to grip in sequence with the other means the ad'acent cheek portion thereof on both si es with equal pressure, and power means applied axially of the chuck body for operatmg both of said means, said power means for the cheek gripping means having an equalizer element therein.

3. In a crank shaft lathe, the combination with the chuck body, having a cavity in which to lay a pin or hearing of a crank shaft, and a pivoted plate having a cavity to come down over .such pin crank, thereby clamping it in place, and wedging means located in the chuck body and movable axially thereof, and connected so as to wedge said plate into position, and fluid pressure means for operating the wedging means.

4. In a crank shaft lathe, the combination with the chuck body, of means thereon to clamp about a pin or bearing portion thereof, and additional means to grip the adjacent cheek portion thereof on both sides, and power means for operating both of said means, said power means for the cheek gripping means having an equalizer element therein, and wedges acting upon the said cheek gripping means, for the purpose described.

5. In a crank shaft lathe chuck, the combination with crank pin or bearing clamping'means, of check gripping means comprising a pair of dogs pivotally secured to the chuck, sliding rods havingwedge ends engaging said dogs, and an equalizer device engaging said rods and imparting sliding motion thereto.

6. In a crank shaft lathe chuck, the combination with crank pin or hearing clampmeans, and comprising a pair of air pressure operated pistons, the rod of one passing through the rod of the other, and connections from the outer rod to one of the two first mentioned means, and the inner rod to the other, thus forming two separately con trolled power elements.

8. In a crank shaft lathe chuck, centering means for the crank shaft, and gripping means therefor to engage two edges of the crank shaft cheek, and means for operating said two means comprising a pair of air pressure operated pistons, the rod of one passing through the rod of the other, and connections from the outer rod to one of said two means, and the inner rod to the other one thereof.

9. In a lathe chuck, two members to engage opposing faces of a portion to be chucked, and means for operating them comprising an equalizer bar pivotally connected to a power actuated element, said bar having forked ends, a pair of operating rods having socket elements thereon for engagement by the said forked ends, so arranged that the forks straddle a portion of the rods, and curved meeting faces on the forks and in the sockets, and connections from the rods to the said two members. I

10. In a lathe chuck, two members to engage opposing faces of a portion to be chucked, and means for operatin them comprising an equalizer bar pivot connected to a power actuated element, said barhaving forked ends, a pair of-op'erating rods havin ment hy the said forked ends, so arranged that the forks straddle a portion ofthe rods and curved meeting faces on the forks an in the sockets, and connections from the rods to the said two members, comprising meansfor confining the motion of the rods to one of reciprocation, and wedge ends on the rods abutting said members.

' WILLIAM F. GROENE, 

